Ground-guided or hand-held work equipment with operating device

Abstract

Ground-guided or hand-held work equipment, in particular garden or forestry equipment, with an operating device (1) comprising a housing body (2) with a substantially tightly sealed, hollow interior (3), a user-operated control element (4) movably held on the housing body (2) which changes a hollow volume (5) of the interior (3) through its actuation movement, and an elastic volume compensation element (6) which is arranged on the housing body (2) in a manner elastically yielding to a gas pressure in the hollow volume (5) of the interior (3) and which is a multi-component injection-molded component which is manufactured together with the housing body (2) or together with at least one part of the housing body (2) adjacent to the volume compensation element (6) by a multi-component injection molding process.

Description

[0001] The invention relates to a ground-guided or hand-held work device with a special operating mechanism. The work device may, in particular, be a corresponding garden or forestry tool. Examples of such work devices include ground-guided tools such as lawnmowers, scarifiers, or the like, as well as hand-held tools such as chainsaws, brush cutters, angle grinders, blowers, pole pruners, hedge trimmers, or the like.

[0002] The operating device of the work equipment under consideration comprises a housing with a substantially sealed, hollow interior and a user-operated control element that is movably mounted on the housing and whose actuation changes the volume of the interior. The term "substantially sealed" in this context means that, during the intended use of the operating device, no liquid media can escape from the hollow interior of the housing to the outside, i.e., into the external environment of the housing, or conversely, from the outside through the housing into the interior. Gaseous media can only pass through the housing at a relatively low rate and consequently relatively slowly. The housing is therefore a sealed housing with, at most, minimal gas permeability.to compensate for pressure changes due to temperature fluctuations.

[0003] The user can operate an associated function of the machine via the control element of the operating device, in particular control it, e.g., switching a motor of the machine on and / or off, or switching the machine between different possible operating modes. Depending on the application, the operating device may also have one or more additional control elements and / or other operator-relevant components, such as sensors, actuators, integrated circuits, microchips or microcontrollers, light-emitting diodes (LEDs), etc.

[0004] Such control devices with sealed housings are used particularly in cases where the components contained within the housing need to be protected from harmful external influences, such as dirt or damaging gaseous or liquid media, and are commonly used, among other things, as so-called HMI (Human-Machine Interface) units. Within the sealed, hollow interior of the housing, relatively slow pressure changes can occur, for example, due to temperature fluctuations.

[0005] It is known to provide a gas-permeable pressure equalization membrane in sealed housings, such as those of HMI units and other similar operating devices. This membrane allows a gaseous medium, such as air, located inside the hollow housing, to be vented to the outside at a relatively low rate in the event of an impending, unwanted overpressure. Such pressure equalization membranes can be used, in particular, to compensate for relatively slow pressure changes, such as changes in air pressure and temperature, which is why they are also referred to as climate membranes in this application. "Relatively slow" in this context refers to changes that do not occur within one or a few seconds or faster, but rather extend over a period of typically at least ten seconds up to several minutes or hours.Such a pressure equalization membrane and its use for sealed housings of electronic control systems in vehicles is disclosed in European Patent Application EP 1 921 020 A1.

[0006] In the operating devices of the type considered here, actuation of the control element changes the volume of the cavity inside the housing. In particular, this change can consist of a reduction in the cavity volume, which results in a corresponding increase in pressure within the cavity. This pressure increase can, in turn, affect the control element, for example, in the form of a resistance force that increases with the actuation stroke of the control element, which the user must overcome to actuate the control element. This effect of the stroke-dependent increase in actuation resistance is usually undesirable and becomes more noticeable the larger the proportion of the volume displaced by the control element is to the total cavity volume, for example, if the control element is relatively large compared to the housing. Thus, the actuation behavior of the control element can be undesirably influenced by the sealed cavity volume.The time scales for such control element actuations, i.e., the typical duration for a complete actuation process of the control element, are typically in the range of at most a few seconds and mostly in the range of one second or less, and consequently below the typical reaction times or pressure equalization times of the gas-permeable pressure equalization membranes mentioned above.

[0007] Patent DE 10 2011 118 178 B3 discloses an illuminated, water- and dust-proof switching element for converting a linear button movement into an electrical switching signal. The element comprises a housing and a cap axially displaceable within the housing by a stroke between two end bearings. The cap is provided with an outwardly sealing protective membrane, which is manufactured from a flexible plastic material using a multi-component injection molding process. The switching element is preferably intended for outdoor use in vehicle construction for switching and / or indicating the operating states of electrical assemblies. Inside the housing are, among other things, a pressure equalization element, which is media-tightly attached by hot or ultrasonic welding, a circuit board on which at least one button is arranged, and a silicone mat as a return element.The pressure equalization element covers a meandering vent channel which is open to the outside to allow pressure equalization between the inside of the switching element and the external environmental conditions.

[0008] Other conventional arrangements with volume / pressure compensating measures, e.g. using elastic volume / pressure compensating elements, are disclosed, for example, in the German patent applications DE 102 59 465 A1 and DE 10 2010 029 446 A1 for actuators in motor vehicles, in the German patent application WO 2013 / 079102 A1 for an electronic housing and in the patent application DE 103 03 962 B4 for an electronic controller for outdoor equipment.

[0009] The invention is based on the technical problem of providing a floor-guided or hand-carried work device of the type mentioned above, in which the operating device offers a high level of user comfort with regard to the operation of the control element, even in cases where the control element is relatively large or its operation results in a relatively large change in the cavity volume of the sealed housing body interior.

[0010] The invention solves this problem by providing a ground-guided or hand-held work device with the features of claim 1. Advantageous embodiments of the invention are specified in the dependent claims, the wording of which is hereby incorporated into the description by reference. This includes, in particular, all embodiments of the invention resulting from the combinations of features defined by the cross-references in the dependent claims.

[0011] In the working device according to the invention, the operating device has an elastic volume compensation element which is arranged on the housing body in such a way as to elastically yield to the gas pressure in the cavity volume of the interior. The volume compensation element, which is pressure-elastic in this sense, can therefore completely or at least partially compensate for the change in the cavity volume of the housing body interior caused by the actuation of the operating element. The volume compensation element and the housing body, or at least a part of the housing body adjacent to the volume compensation element, are manufactured using a multi-component injection molding process known per se; that is, the volume compensation element is a multi-component injection-molded component which, together with the housing body or together with at least a part of the housing body adjacent to the volume compensation element, is manufactured by a multi-component injection molding process.

[0012] For example, if the control element is actuated in such a way that it moves towards a reduction in the cavity volume and consequently compresses the gas (such as air) inside, increasing the pressure, the volume compensation element elastically yields to the increasing gas pressure and expands, i.e., moves or deforms towards an increase in the cavity volume. Thus, in this case, the volume compensation element increases the cavity volume completely or partially to the extent that the control element reduces the cavity volume when actuated. This allows the gas pressure in the cavity to be kept essentially constant when the control element is actuated, which in turn means that a feedback effect of the gas pressure on the control element, dependent on the actuation stroke of the control element, can be avoided.

[0013] In other words, the volume compensation element counteracts the change in the cavity volume caused by the moving control element and thereby completely or at least partially compensates for the influence of the control element on the cavity volume, so that an undesirable reaction of the gas pressure in the interior of the housing body or in its cavity volume on the operating behavior or on the operating haptics of the control element for the user is avoided.

[0014] Compared to gas-permeable pressure equalization elements, the pressure-elastic volume equalization element provides a significantly faster response to the pressure change caused by actuating the control element, which typically occurs within a few seconds at most, usually within one second or less. Therefore, the volume equalization element is well-suited to assist or even effect the return of the control element to its original position when needed, for example, by elastically contracting and reducing the cavity volume when the control element returns to its initial position, thereby releasing additional cavity volume.

[0015] Through the interaction of the elastically yielding and contracting volume compensation element with the cavity-changing movement of the control element, optimal operating behavior of the control element can be provided for the user in the sealed control device housing according to the invention.

[0016] Due to its elastically compliant pressure equalization behavior, the volume compensation element is able to support the return movement of the control element from an actuated position to its initial position. If required, the volume compensation element can be configured to automatically move the control element back from the actuated position to its initial position within a predetermined return time. In this case, the volume compensation element ensures that the control element returns from the actuated position to its initial position without requiring any force from the user or the control device needing to have another return component, such as a return spring or the like. The return time can be set to, for example, approximately...A delay of one second or less is specified, which is optimal in many cases so that the control element can be operated again afterwards and / or so that the user receives a favorable or familiar haptic feedback regarding the operation of the control element.

[0017] Optionally, the volume compensation element can also be configured as a gas-permeable pressure compensation element of the type mentioned above, thereby compensating for temperature-related pressure fluctuations within the housing body on a slower timescale. Alternatively, the volume compensation element can be gas-tight. If required, the operating device can also be equipped with a conventional gas-permeable pressure compensation element.

[0018] In a further development of the invention, the control element is operable between a starting position and an actuated position and, when actuated in the direction of the actuated position, reduces the volume of the cavity. Thus, in this case, the actuation of the control element by the user results in a pressure increase in the cavity due to the volume reduction. The volume compensation element reacts to this increase by elastically yielding to the increased pressure, thereby counteracting the volume reduction of the cavity caused by the control element by increasing the volume and thus compensating for the volume-reducing and pressure-increasing effect of the control element actuation.In particular, the effect of the volume compensation element allows the internal volume of the housing body to be kept essentially constant during operation of the control element, as well as the pressure within the internal volume. In alternative designs, the control element increases the internal volume when actuated in the direction of the actuation position. In this case, the volume compensation element counteracts the volume- and pressure-changing effect of the control element actuation by elastically yielding to the pressure decrease, i.e., the negative pressure, within the internal volume, thus reducing the internal volume.

[0019] In a further development of the invention, the control element comprises a push-button element. This represents an advantageous embodiment of the control element for many applications of the operating device, e.g., in a function as an on / off push-button switch element. The control element can consist entirely of the push-button element or, in addition to the push-button element, include one or more further components. Alternatively, the control element is designed in a different conventional manner, e.g., as a user-operated or controllable control element without physical contact or as a force-operated control element.

[0020] In a further development of the invention, the volume compensation element forms a receiving space for a component arranged inside the housing body. This measure allows the volume compensation element to be advantageously used to accommodate the relevant component of the operating device inside the housing body.

[0021] In one embodiment of the invention, the component arranged inside the housing body is an electrical battery element. This embodiment is particularly suitable for operating devices with their own electrical power supply in the form of the electrical battery element arranged inside the housing body, which in this case can be housed in the receiving space formed by the volume compensation element. In alternative embodiments, another component of the operating device, such as a sensor element, an integrated circuit, or a microcontroller, etc., can be housed in the receiving space of the volume compensation element.

[0022] In a further development of the invention, the control element and the volume compensation element are arranged on two opposite sides of the housing body. This opposite arrangement of the control element and the volume compensation element offers advantages for many applications with regard to the design of the control device and with regard to the volume-compensating and thus pressure-compensating function of the volume compensation element. In alternative embodiments, the volume compensation element is, for example, arranged on the same side of the housing body as the control element or on a side of the housing body that adjoins the side of the housing body on which the control element is located.

[0023] In one embodiment of the invention, the control element is arranged on a user-facing side of the housing body, and the volume compensation element is arranged on a user-away side of the housing body. Arranging the control element on the user-facing side of the housing body is generally advantageous for particularly good accessibility and thus ease of use by the user, while the volume compensation element can fulfill its elastically yielding, volume-compensating function on the user-away side of the housing body, leaving the user-facing side of the housing body unaffected. In alternative embodiments, the control element is located on a side of the housing body different from the user-facing side if this is advantageous for the specific application.

[0024] In a further development of the invention, the volume compensation element is formed from a pressure-elastic material. This represents a manufacturing-technically and functionally advantageous embodiment of the volume compensation element. Since it is formed from the pressure-elastic material, it elastically responds to the pressure change caused by the actuation of the control element due to the volume change of the cavity inside the housing body, simply by virtue of its material properties. This ensures the desired volume / pressure compensation and, if necessary, provides support for the return movement of the control element to its initial position through an elastic restoring force. In particular, the pressure-elastic material can be a rubber-elastic material, specifically a rubber material or a thermoplastic elastomer (TPE). In alternative embodiments, the volume compensation element is formed, for example, by a spring-elastic element.

[0025] In a further development of the invention, the control element is an electrical switch for turning a motor of the ground-based or hand-held work device on and off. This represents an advantageous embodiment of the control device and, in particular, of its control element, which in this case can serve to turn on and / or off a motor present in the work device, such as a drive motor for a lawnmower cutting unit or a drive motor for a chainsaw chain.

[0026] Advantageous embodiments of the invention are illustrated in the drawings. These and further advantageous embodiments of the invention are described in more detail below. The drawings show: Fig. 1. A perspective view of a lawnmower with a schematically depicted operating device, Fig. 2 a partial perspective view of a chainsaw with a schematically depicted operating device, Fig. 3 A perspective view from the front of a control device, such as that found on the lawnmower of Fig. 1 or in the case of the chainsaw from Fig. 2 usable, Fig. 4 a perspective view from behind of the operating device of Fig. 3, Fig. 5 a view of an inside of one housing half of the operating device of Fig. 3, Fig. 6 a longitudinal section view along a line VI-VI of Fig. 3 and Fig. 7 the view of Fig. 6 when an operating element of the operating device is activated.

[0027] The Fig. 1 and Fig. Figure 2 illustrates two exemplary examples of the ground-guided or hand-held work device according to the invention. Specifically, it shows... Fig. 1. A ground-guided work device in the form of a motor-driven lawnmower 9, which, according to the invention, is equipped with an operating device 1a and is otherwise of a conventional design, which therefore requires no further explanation here. In the example shown, the operating device 1a is arranged on a handle 11 of the lawnmower 9, which is gripped by the user when operating the lawnmower 9 in order to guide the lawnmower 9 by hand. The lawnmower 9 includes, in a conventional manner, a mower housing 21 in which, among other things, a motor 16 is arranged, which drives a rotating cutting tool and can optionally also serve to drive rear wheels 12 or front wheels 13 of the lawnmower 9.

[0028] Fig. Figure 2 shows in particular a chainsaw 10, which is also equipped with an operating device 1b in accordance with the invention and otherwise has a conventional design which does not require further explanation here, wherein the chainsaw includes a motor 17 housed in a saw housing 14 for driving a saw chain 15 which is only partially shown.

[0029] The Fig. Figures 3 to 7 illustrate an operating device 1, which in this or a similar design is the operating device 1a of the lawnmower 9. Fig. 1 or as operating device 1b of the chainsaw 10 of Fig. 2 or can be used for another ground-guided or hand-carried work device according to the invention.

[0030] How from into the Fig. As shown in Figures 3 to 7, the operating device 1 includes a housing body 2 with a substantially tightly sealed, hollow interior 3 and a user-operated control element 4 which is movably held on the housing body 2 and which changes a hollow volume 5 of the interior 3 through its actuation movement.

[0031] In the example shown, the housing body 2 consists of two housing shells or housing halves 2a, 2b, which are joined together along a circumferential dividing line 18 in a liquid-tight and completely or largely gas-tight manner and are connected to each other, for example, by means of screw connections. These could be, for example, a front upper housing shell and a rear lower housing shell. The dividing line 18 runs along a narrow side edge of the housing body 2, which is located between a first main housing side 2v and an opposite, second main housing side 2r.

[0032] Furthermore, the operating device 1 includes an elastic volume compensation element 6, which is arranged on the housing body 1 and is designed to elastically yield to gas pressure in the cavity 5 of the interior 3. This enables the volume compensation element 6 to compensate for the volume change, and thus also the pressure change, in the cavity 5 of the housing body interior 3 caused by the actuation of the operating element 4. This compensation effect of the volume compensation element 6 is particularly useful when the operating element 4, as in the example shown, has a relatively large surface area, i.e., occupies a significant portion of the housing body and therefore noticeably changes the cavity 5 of the interior 3 when actuated. Without the volume compensation element 6, this influence of the operating element 4 on the volume change, and thus on the pressure change, in the cavity 5 could lead to an unsatisfactory user experience.In contrast, the volume compensation element 6 allows the user to experience an optimal operating feel in this case as well, just as they are used to from operating devices without a sealed housing.

[0033] In corresponding embodiments, the control element 4, as in the example shown, is located between a Fig. 6 shown starting position AS and one in Fig. The actuation element 6 can be operated in the actuation position BS shown in Figure 7 and, when actuated in the direction of actuation position BS, reduces the volume of the cavity 5 of the interior 3. The reduction in the volume of the cavity 5 caused by actuating the control element results in a pressure increase within the cavity 5. The volume compensation element 6 elastically yields to this pressure increase, so that the cavity 5 of the interior of the housing 3, and thus also the pressure within the cavity 5, remains essentially constant despite the actuation of the control element. This makes it easier for the user to operate the control element 5 and provides the aforementioned good operating feel and optimal haptic feedback.

[0034] In advantageous embodiments, the volume compensation element 6 possesses an elastic restoring function, with which it automatically returns from an elastically deformed position 6', as in Fig. The volume compensation element 6, shown with a dashed line, returns to its initial position when the control element 4, after being actuated, moves from its actuation position BS back to its initial position AS, thereby reversing the volume and pressure change in the cavity 5 of the housing interior 3 caused by the actuation of the control element. Optionally, the volume compensation element 6 can be designed to support the return movement of the control element 4 to its initial position with an elastic restoring force, which is transmitted to the control element 4, for example, via the gas pressure in the cavity 5 of the housing interior 3. If required, the volume compensation element 6 can further be designed so that its elastic restoring force automatically returns the control element 4 to its initial position.without user intervention and without any other reset component, it moves from its actuation position BS back to its initial position AS within a predetermined reset time, which is, for example, at most approximately 1 second and preferably less than half a second.

[0035] In advantageous embodiments, the control element 4 comprises, as in the example shown, a push-button element 4'. In the example shown, the push-button element 4' acts on a lever element 19 mounted on one side of the housing body 2, which in turn acts at its free end region on a release element 20 to trigger a desired operating function.

[0036] Specifically, the control element 4 can be, for example, an electrical switch element for switching on / off the motor 16, 17 of the lawnmower 9 or the chainsaw 10, or for providing another operating or control function for the motor 16, 17 of the lawnmower 9 or the chainsaw 10.

[0037] In advantageous embodiments, the volume compensation element 6, as in the example shown, forms a receiving space 7 for a component 8 arranged in the interior 3 of the housing body 2. For this purpose, the volume compensation element 6 has a region 6a with a suitable shape that defines or delimits the receiving space 7.

[0038] In corresponding implementations, the component 8 arranged in the interior of the housing body 3 is an electrical battery element 8'. In the example shown, this is a button cell battery, with the volume compensation element 6 providing the receiving space 7 in a flat cylindrical shape suitable for receiving the button cell battery. For this purpose, the volume compensation element 6 is designed in a pot-shaped form in the associated area 6a.

[0039] In advantageous embodiments, the volume compensation element 6 is formed from a pressure-elastic material, preferably from a rubber-elastic material or, more specifically, from a rubber material or a thermoplastic elastomer (TPE). In particular, the volume compensation element 6 can be formed from a pressure-elastic membrane; in the example shown, this is the case, as can be seen in particular from the Fig. 4 and Fig. 5, specifically a substantially strip-shaped membrane 6m, which in a central area has the pot-shaped region 6a as a pot-shaped bulge to provide the receiving space 7 for the button cell battery and which is fixed to the housing body 2 with its circumferential edge. In particular, with its pot-bottom region 6a, the volume compensation element 6 in this embodiment can elastically yield to pressure changes in the cavity 5 of the housing body interior 3. Fig.Figure 7 shows, with a dashed line, the path of the volume compensation element 6 thus realized in the elastically yielding position 6' with the pot bottom convex outwards relative to the interior of the housing body 3, compared to its initial position with a substantially flat pot bottom. The membrane 6m can, for example, be injection-molded onto the housing body 2 as a rubber-elastic membrane body and thus fixed to it. For this purpose, the volume compensation element 6 and the housing body 2, or at least a part of the housing body 2 adjacent to the volume compensation element 6, are manufactured by a multi-component injection molding process.

[0040] In advantageous embodiments, the control element 4 and the volume compensation element 6 are arranged on two opposite sides of the housing body 2. Specifically, in the example shown, the control element 4 is arranged on the first main housing side 2v and the volume compensation element 6 on the opposite, second main housing side 2r. The first main housing side 2v can, for example, be a user-facing side 2a of the housing body 2, and the second main housing side 2r can be a user-away side 2b of the housing body 2. In this case, the side of the housing body 2 on which the control element 4 is located is therefore facing the user when the user is operating the device.

[0041] As the illustrated and further embodiments explained above clearly demonstrate, the invention provides a ground-guided or hand-held work device, such as a lawnmower, a chainsaw, etc., with an operating device that enables the user to operate the control element very comfortably and reliably, thereby facilitating a corresponding operating or control function for the work device, such as switching an electric or combustion engine of the work device on or off. The operating device has a sealed housing, and the special design of the operating device with the pressure-elastic volume compensation element provides the user with an optimal operating feel and, in particular, a favorable haptic feedback.Haptic feedback for the operation of the control element is also necessary in cases where the control element has a relatively large surface area and its operation results in a noticeable change in the volume of the sealed cavity enclosed within the housing. Conversely, a large control element can make it easier for the user to operate.

Claims

[1] Ground-guided or hand-held work equipment, in particular garden or forestry equipment, with an operating device (1) comprising a housing body (2) with a substantially tightly sealed, hollow interior (3), a user-operated control element (4) movably held on the housing body (2) which changes a hollow volume (5) of the interior (3) by its actuation movement, and an elastic volume compensation element (6) which is arranged on the housing body (2) in a manner elastically yielding to a gas pressure in the hollow volume (5) of the interior (3) and which is a multi-component injection-molded component which is manufactured together with the housing body (2) or together with at least one part of the housing body (2) adjacent to the volume compensation element (6) by a multi-component injection molding process. [2] Working device according to claim 1, further characterized by, that the control element (4) can be actuated between a starting position (AS) and an actuation position (BS) and, when actuated in the direction of the actuation position (BS), has a volume-reducing effect on the cavity volume (5) of the interior space (3). [3] Working equipment according to claim 1 or 2, further characterized by , that the control element (4) includes a push button element (4'). [4] Working device according to one of claims 1 to 3, further characterized by , that the volume compensation element (6) forms a receiving space (7) for a component (8) arranged in the interior of the housing body (3). [5] Working device according to claim 4, further characterized by , that the component (8) arranged in the interior of the housing body (3) is an electrical battery element (8'). [6] Working device according to any one of claims 1 to 5, further characterized by, that the control element (4) and the volume compensation element (6) are arranged on two opposite sides (2v, 2r) of the housing body (2). [7] Working device according to claim 6, further characterized by , that the control element (4) is located on a user-facing side (2a) of the housing body (2) and the volume compensation element (6) is located on a user-away side (2b) of the housing body (2). [8] Working device according to any one of claims 1 to 7, further characterized by , that the volume compensation element (6) is made of a pressure-elastic material. [9] Working device according to any one of claims 1 to 8, further characterized by , that the control element (4) is an electrical switching element for switching on / off a motor (16, 17) of the ground-guided or hand-carried work device.

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